Boiler-feed-water-supply plant



July 13- 1926.

1,592,195 H. FOTHERGILL BOILER FEED WATER SUPPLY PLANT- Filed March 5, 1924 /NvE/-/To: HAQ FoTHEEGmL ihe object of '15 nanny ro'rnnnemn, or wnsrnmsrna. LONDON, ENGLAND.

nomnn-rnnn-warnn-surrny PLANT.

' Application filed march 5, 1e24, Serial no. 697,104,-and in Great Britain amt-9, 1923.

This invention relates to improvements in or relating to steam turbine plant 1n which means are provided for removing the air from the boiler feed water by. heat treatment in a vessel generally called a deaerating apparatus. In steam power plants, it frequently happens, iaries are electrically driven, not sufficient low pressure steam available for heating the temperature, and steam is bled from a steam {turbine and usedin aseparate feed water heater for this purpose. V

, the presentfinvention is to utilize steam bled from the turbine for feifectingatone and the same time the dual operation, of heating and deaerating the feed water.

When it is desired to maintain a low sure .in the chamber. in which the water is so perature pressure in; the chamber in which the water is-d'eaerated by placing it in connection with a main condenser under vacuum, I prefer to arrange in such connection a nozzle or equivalent device for the purpose of limiting to apredetermined amount the quantity of. aerated vapourpassing from'the deaerator to the condenser by the choking eifect of the nozzle. By this means the presdeaeratedis automatically adjusted to that pressure corresponding to the boiling point of the water, notwithstanding variations in the-"quantity of water treated in the, deaerator, or in the steam available for heating,

' because by the use of fa free opening such as nozzle the pressure in the deaerator adjusts itself to maintain the production ofthe, water vapor necessary to fill the nozzle opening o p The deeerating apparatus may be of the type in which the water is raised in temby direct contact with the steam, but I prefer the arrangement in which the water is heated by surface contact.

The accompanying drawing illustrates an embodiment of'my invention wherein a deaerator is employed in which the heat treat rnentiis e ted by surface contact.

the arrangement illustrated a is the main turbine, bthefdeaerator and c the main COD-.- dens'er' -frprn"which the air is removed by the ejector d. The pump a removes the condensate froin the condenser c and discharges through the pipe f into the deaerator b ahrom which the deaerated water is removed pipeg by the pump Low pressure,

especially where auxil-, that there is feed waterto the desired" shown,

' the pipe p;

steam is bled from the turbine through the pipe Z under control of the valve m and 1s used in the the desired temperature. at is a drain connection through which the condensed steam from the tubes is dischargedainto'the condenser 0. The deaerator b isniaintained under vacuum by placing it in commufnica- 'tion with the condenser c by way of the p1pe p.

'This pipe p is provided with a nozzle or equivalent device ofor the purpose of limiting to a predetermined amount the quantity of aerated vapour passing from the deaerator b to, the condenser c by tubes 2, for raising the water to the choking effect of the deviceo. Any re- 'stricted opening in the pipe p will give this desired effect, and in the arrangement an-ordinary valve, opened tothe desired extent, is illustrated. By the use of this restricted opening the pressure in the deaerator is maintained at that corresponding to the temperature of the water therein,

while a predetermined amount of aerated" vapour is continuously dischargedthrough By using bled steam from a low pressure section of the turbine it follows that the quantity of such bled steam will Vary inacoordance' with the load on the turxbinej thereforeethis method of working has the great advantage that the steam supply is automatically adjusted and no special device for this purpose need be provided. For example, when the turbine 1s under light load, the pressure in the low pressure section less steam will pass to the deaerator. Alternatively, if the turbine is under .full load,

- the pressure in the low pressure section is increased and more'steam will passto the deaerator. a

ylUnder such conditions the tendency will be automatically to deliver steam to the deaerator in correspondence with the water passing 'therethrough.

What I claim and desire to secure by Letters Patent is 3 p 1. gteam power plant comprising a steam turbine, facondenser to which said turbine exhausts, a deaeratlng' apparatus, a connee' tion between the deaerating apparatus, and

the condenser for maintaining the deaeratvice in said connection for limiting the mg apparatus under vacuum, a choking deof the turbine will be reduced and quantity of aerated vapour passing from the deaerating apparatus to'the condenser, means for conveying the heated and deaerated' water from the deareating apparatus to the boiler feed system.

2. Steam power plant comprising a steam turbine, a condenser to which said turbinev exhausts, a deaerating apparatus, a connection between the deaeratlng apparatus and the condenser for maintaining the deaerating apparatus under vacuum, a valve in said,

connection for limiting to a predetermined amount the quantity of aerated vapour passing from the deaerating apparatus to the condenser, means for delivering condensate from the condenser to the Generating apparatus a connection between the turbine and the deaerating apparatus io'i conveying steam from said turbine to said deaerating apparatus, and means for conveyin the heated and deaerated water from the eaerating apparatus to the boiler feed system.

3. Steam power plant comprising a steam turbine, a condenser towhich said turbine exhausts, deaerating apparatus provided with heating tubes, means for delivering condensate from the condenser to the deaerating apparatus, so as tofall on said tubes, a connection between the turbine and the deaerating apparatus for conveying steam from said turbine to and through the tubes of said deaerating apparatus, a drain connection from the deaeratingapparatus to the condenser through which -the condensed steam from the tubes of the deaerating apparatus is delivered to the condenser, and means for conveying heated and deaerated water from the deaerating apparatus to the boiler feed system;

4. Steam power plant comprisin a steam turbine, a condenser to which sai turbine exhausts, a deaerating apparatus, having steam heated surface, a connection between the deaerating apparatus and the condenser for maintaining the deaerating apparatus under vacuum, means for delivering condensateifrom the condenser to the deaeratin apparatus, so as to fallon the steam heated surface, a connection between the turbine and the deaerating apparatus for conveying steam from said turbine to'heat the surface Within said deaerating apparatus, means for draining'the condensed steam from theheating surface of the deaerating apparatus to the condenser, and means for conveying the heated-and deaerated water from the deaerating apparatus to the boiler feed system.

In testimony whereof I aflixmy signature..

HARRY FOTHERGILL. 

